#define  _CRT_SECURE_NO_WARNINGS 1 
#include<stdio.h>

int main()
{
	int i = 0;
	int count = 1;
	for (i = 11; i <= 100; i++)
	{
		if (i / 10 == 9)
			count++;
		if (i % 10 == 9)
			count++;
	}
	printf("%d\n", count);
	return 0;
}